"""
    模块的封装
"""
# 对外暴漏的方法和属性
__all__ = ["num","add"]
num = 100
num2 = 200
def add(a,b):
    return a + b

if __name__ == "__main__":
    print(f"__name__ is {__name__}")
    print(f"add method exec result is : {add(10,20)}")